The invention relates to a process and a catalyst for polymerization of vicinal alkylene oxides to very high molecular weights in a fashion by which the molecular weight of the polymers can be easily controlled by adjusting the amount of one of the components of the catalyst in a specified fashion.
Previously, polyethers of high molecular weight have been made by contacting with catalysts prepared from various organometallic compounds, specifically zinc and aluminum alkyls, aluminum hydrides, or ferric chloride complexes.
U.S. Pat. No. 2,706,181 shows the preparation and utilization of a catalyst for polymerization of olefin oxides which catalyst is the condensation product of a ferric halide and propylene oxide. U.S. Pat. No. 2,870,100 illustrates the utilization of organoaluminum, organozinc or organomagnesium compounds as catalysts for alkylene oxide polymerization. U.S. Pat. No. 2,801,228 teaches the use of aluminum, nickel, cobalt and copper-acetyl acetone compounds as "hardening agents" for polyepoxide resins. U.S. Pat. No. 3,219,591 describes the utility of alkyl aluminums modified with water and optionally a .beta.-diketone as polymerization catalysts for alkylene oxides. U.S. Pat. No. 3,186,958 shows alkyl aluminums in combination with secondary amines and optionally water as alkylene oxide polymerization catalysts. U.S. Pat. No. 3,301,796 describes alkyl aluminum or alkyl zinc compounds in combination with an active hydrogen co-catalyst which may be water, an alkanol, a primary or secondary amine, or an amide in combination with nitroaromatic hydrocarbons as alkylene oxide polymerization catalysts and U.S. Pat. No. 3,499,847 and 3,617,571 also describe alkyl aluminums plus a nitroaromatic compound optionally with a .beta.-diketone and water. In U.S. Pat. No. 3,532,644, the catalysts of the 3,617,571 patent are employed and, after polymerization is completed and the catalyst is deactivated, antioxidants including phenothiazine are added to the polymer.
So far as the Applicants know, only U.S. Pat. No. 3,394,088 shows the combination of a secondary amine with an aluminum compound and additionally the optional components of water and a .beta.-diketone. However, this patent teaches that the catalyst is an inorganic-type catalyst which does not contain any direct aluminum to carbon bond. Comparison of such catalysts with those catalysts instantly claimed shows the catalyst of the present invention to be more effective for the production of high molecular weight vicinal alkylene oxide polymers.